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排序方式: 共有274条查询结果,搜索用时 62 毫秒
271.
Funabiki K Mase H Saito Y Otsuka A Hibino A Tanaka N Miura H Himori Y Yoshida T Kubota Y Matsui M 《Organic letters》2012,14(5):1246-1249
Novel near-infrared (NIR)-sensitizing (up to 800 nm) simple asymmetric squaraine dyes (Sq 31 and Sq 33) carrying indoline moieties that did not require the introduction of any linker groups were developed. DSSCs fabricated with Sq 33 exhibited remarkable characteristics in the long-wavelength visible and NIR region (up to 800 nm), such as a conversion efficiency of 3.75% (AM 1.5G) with an incident photon-to-current conversion efficiency of 63% (650 nm), a short-circuit photocurrent density of 13.64 mA, an open-circuit photovoltage of 0.48, and a fill factor of 0.57. 相似文献
272.
Kadota I Nishii H Ishioka H Takamura H Yamamoto Y 《The Journal of organic chemistry》2006,71(11):4183-4187
An efficient synthesis of the A-G ring segment 2, a key intermediate for the total synthesis of brevetoxin B (1), was achieved in 37 steps and 5.0% overall yield. The intramolecular allylation of the O,S-acetal 22, prepared from the ABC ring segment 15 and the FG ring segment 17, was carried out using AgOTf as a Lewis acid to give the desired compound 23, predominantly. Ring-closing metathesis of 23 with the Grubbs catalyst 12 afforded the heptacyclic ether 25. Selective hydrogenation of the E ring olefin of 25 was performed by diimide reduction to afford 2. 相似文献
273.
Gas transport properties of asymmetric polyimide membranes prepared by plasma‐based ion implantation
Teppei Tezuka Tomohiro Kobayashi Daigo Muraoka Shoji Nagaoka Yoshiaki Suzuki Hiroyoshi Kawakami 《先进技术聚合物》2009,20(12):987-992
In this study, we report the gas permeance and selectivity of the asymmetric polyimide membrane prepared by plasma‐based ion implantation (PBII). The asymmetric polyimide membranes were prepared using a dry–wet phase inversion process, and the surface skin layer on the membrane was implantated by He ions at 2.5 keV. The asymmetric membranes treated by PBII were measured using a high vacuum apparatus with a Baratron absolute pressure gauge at 76 cmHg and 35°C. The (O2/N2) and (CO2/CH4) selectivities in the He+‐implanted asymmetric membrane at 60 sec resulted in 1.5 and 1.8 time increases, respectively, when compared to those of the asymmetric membrane before PBII. On the other hand, the O2 and CO2 permeances in the asymmetric membrane after PBII decreased with an increase in the He+ treatment time. In this paper, we addressed, for the first time, the gas permeation behavior of the asymmetric polyimide membranes prepared by PBII. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
274.
Yasuhide Okumoto Hiroyoshi Fujiki Junji Kawakami Shoji Nakashima Shu-ichi Nakano Tatsuo Ohmichi Daisuke Miyoshi Naoki Sugimoto 《Macromolecular Symposia》2003,201(1):245-252
We report the potential of a small Ca2+-dependent deoxyribozyme as a novel biomaterial to distinguish RNA foldings. It is found that an immobilized deoxyribozyme using avidin-biotin interaction cleaves the target site within only single-stranded RNAs. The RNA cleavage reaction is also detected using the deoxyribozyme SPR sensor chip. Furthermore, we develop a novel NAPzyme (nucleic acid peptide deoxyribozyme) with its RNA cleavage function in the absence of divalent metal ions. 相似文献